iPhone Does dark mode reduce battery drain?

DaveOP

macrumors 65816
May 29, 2011
1,499
2,090
Portland, OR
Kind of hoping it adds to the runtime.
After running the betas all summer, it didn't feel noticable. Obviously, Betas are not always battery optimized so that's not a super great test. I suspect it won't be substantial unless you're the type to check screen-on time in settings.
 

dannyyankou

macrumors G3
Mar 2, 2012
8,722
12,953
Scarsdale, NY
It does if done right. If it’s true black, where the pixels are turned off, it does.

But if it does what some apps are doing (and this forum lol) where it’s dark grey, it won’t reduce battery drain.
 

zorinlynx

macrumors 603
May 31, 2007
5,730
7,089
Florida, USA
It does if done right. If it’s true black, where the pixels are turned off, it does.

But if it does what some apps are doing (and this forum lol) where it’s dark grey, it won’t reduce battery drain.
That doesn't make sense. Surely an OLED pixel displaying dark grey will use less energy than one displaying white?
 

dannyyankou

macrumors G3
Mar 2, 2012
8,722
12,953
Scarsdale, NY
That doesn't make sense. Surely an OLED pixel displaying dark grey will use less energy than one displaying white?
I don’t think that’s the case. When they say “true black”, they mean individual pixels are switched off. If pixels are lit grey, they’re still on and will use energy. Not sure if it’s less energy than white pixels, but if you want to save battery it should be “true black”.
 

d.steve

macrumors 6502
Jan 6, 2012
288
101
So yeah, it does require energy to make an LCD/LED pixel dark, so a dark pixel requires (more) energy.

However, you have to also consider the energy that goes into any backlighting. Dark mode on screens where backlighting is dynamic is better where the backlighting is more energy intensive than the sum of all dark pixels.
 

Wilson1313

macrumors member
Nov 29, 2008
95
169
There had been some tests on this, and OLED screens definitely do save power using black text. For an LCD screen, the backlight has to be always on regardless if there are black pixels on the display (black is essentially just achieved by putting a filter over the backlight). For OLED, each pixel is independently controlled so a majority black screen will have the pixels either off or at very low power.

 
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